The mission of the Imaging and Cytometry Facility Core (ICFC) is to support established, peer-reviewed, funded research programs of EHS Center members by providing access to contemporary technology, instrumentation, and services in microscopy and flow cytometry at little or no cost to individual investigators. The ICFC enhances the research productivity of Center members by providing the instrumentation, training, and expertise necessary to successfully adopt microscopic, flow cytometric, and imaging techniques into both their individual and collaborative research programs. During the past funding period, the 30 investigators utilizing ICFC services and facilities have published 83 manuscripts and received funding for 29 grants (new and renewal), with another 3 pending, utilizing data generated through ICFC use. Access to these technologies is essential for pursuing studies in environmental, cellular, and molecular toxicology, especially those in signal transduction. The ICFC has fostered multi-disciplinary collaborative research in the areas of xenobiotic effects on a variety of cell/organ systems, the effects of heavy metals on cell function and signalling, the regulation of xenobiotic metabolizing enzyme gene expression, DNA repair in response to toxic insult, regulation of cellular signalling pathways, cellular responses to oxidative stress, and T-cell phenotype association with asthma susceptibility. The ICFC are to attract new users and new Center members. Since the last competitive renewal, 16 new users, all Center members, have utilized the ICFC services/facilities. The ICFC facilitates the introduction of new approaches to investigators' individual and collaborative research programs through the provision of services requiring little initial input of time or money on the part of the investigator. The ICFC provides access to technologies and instrumentation that would otherwise be unavailable to individual investigators, and strives to introduce new technologies in response to the Center investigator needs. Advanced equipment is maintained and operated by expert core personnel, who provide service, guidance, and training to EHS Center members using the facility. Investigators can receive hands-on training in light, confocal, and fluorescent microscopy, immunocytochemistry, flow cytometry and cell sorting, and the comet assay. The ICFC also maintains equipment and instrumentation for sample analysis (e.g., spectrophotometers, fluorometer, luminometer, Agilent Bioanalyzer) and data acquisition (e.g., gel documentation system, film developer, scanning laser densitometer). The goal of the ICFC is to acquire and maintain these instruments and services in a functional multi-user environment normally unavailable to individual investigators.